It uses Appium, which provides a Selenium WebDriver compatible API
to remotely control an iOS (or Android) simulator. This way we can
run tests in both mobile OSes without big changes to the current
test code and infrastructure.

This allows user to customize in the test suite module on which
system they want to run the tests (Firefox or iOS) through the
slapos parameters. In iOS, for example, it's possible to change
the iOS version and it's required that the user give the SauceLabs
credentials in form of user:apikey using the `appium_server_auth` parameter.

An example of parameters to use in a test suite:

```
{
  "mariadb": {
    "relaxed-writes": true,
    "mariadb-relaxed-writes": true,
    "test-database-amount": 30
  },
  "target": "iOS",
  "target-version": "9.3",
  "target-device": "iPhone Simulator",
  "target-browser": "Safari",
  "appium-server-auth": "username:auth_token",
  "test-suite" : "jio" ,
  "test-url": "jio-repository.git/test/tests.html"
}
```